Biological Approach Flashcards
Assumptions
human behaviour explained by hormones, genetics, evolution etc.
behav modified or removed using biological treatments as it is caused by biological causes
Influence of genes on behaviour
- faulty genes cause diseases that have psychological effects
- look at genes that make people more likely to develop mental illnesses
- twin studies very useful for investigating
Gottesman (1991)
- meta-analysis of 40 twin studies
Findings(Gottesman)
having identical twins with schizophrenia gave you a 48% chance of developing teh condition - reduced to 17% in non-identical
twins
However,
fact both twins developed schizophrenia in only about half the cases means other factor involved maybe environment.
Conclusions(Gottesman)
- your nature has big impact on developing schizophrenia as identical twins have 100% same genetics, therefore higher chance of developing the condition compared to non-identical with only 50% shared
Heston (1966)
an adoption study of schizophrenia
What happened in study…
- 47 adopted children - biological mothers had schizophrenia were studied
- control group: 50 adopted children whose mothers didn’t have schizophrenia: interviewed as adults and given personality and intelligence tests.
Results(heston)
in experimental group 5 of the 47 became schizophrenic, 4 borderline, 0 in control group were
Study supports…
that your genetics do play a part in the development of schizophrenia
BUT…
interview data can be unreliable and affected by what the person considers right or acceptable, social desirability bias
Genetics overview
- egg & sperm join to make 46 chromosomes (23 each)
- chromosome made up of DNA
- genotype: collection of all the genes with each cell of an individual.
- phenotype: the characteristics that genes produce - can refer to behaviour from interaction between genotype & environment.
Moderators
environment, peer group, schools, parents, education, media, biological factors (non-DNA)
Neurochemistry
study of chemical processes which take place in the nervous system
Receptor
specialised cells that detect stimuli.
Stimulus
changes in the environment
Effectors
carry out the response and are either muscles or glands
CNS
the brain and the spinal cord
Nerve
a bundle of neurons
Nerve impulse
electrical message that passes along a neuron
In the brain transmission…
of chemicals is in the cerebral fluid these are called neurotransmitters
Phineas Gage: man with a hole in his head
- accident with rocks, spark created and causes a hole in his head.
- kept on living for another 12yrs
- however was a changed man: he was unreliable, partial to swearing & made inappropriate remarks - make disinhibited
Was important to scientists as…
first time that damage to our brain could affect our behaviour and personality
-scientists came up with diff theories
- localisation
- showed all
parts of brain
could do
everything.
Scans
PET - shows which part of brain is most active when thinking about diff things.
CAT - detect damaged parts of the brain
MRI - detailed info about brain structure.
Maguire et al (2000)
study of taxi drivers brains
Maguire et al (2000)
- in natural experiment, MRI scans from 16 licensed taxi drivers were compared with a control group who had never driven taxis.
- Average size of right posterior hippocampus was significantly larger in the taxi driver group, compared to control
- increased size relative to amount of time the driver had been working
Conclusion(Maguire)
- longer time driving & working, larger hippocampus compared to control group
Practical Application(Maguire)
used to help those with brain injuries as shows size of the structures are linked to cognitive activity.
Rehabilitation can be tailored to specific needs of individual.
Evaluation: Strengths
- if we know how it is caused we are able to come up with a solution
Look for biological markers makes it more objective and reliable. However, treatments limited as we don’t know why they have it.
Able to keep an eye on people who are predisposed so there can be early intervention and help.
Provides scientific evidence to prove/disprove a theory
Evaluation: weaknesses
Reductionist (largely
- it oversees some of the complexities seen in behaviour + those moderate variables
- variables outside of biology needs to be taken into account to understand behav
Evaluation: weaknesses
Determinism
- human behav explained by genetics, can’t choose your genetics (no-free will)
- criminal responsibility?
- removes social responsibility as can just blame it on there genes